I wanted to try the Trainer before i buy it. But everytime i activate Inf. health, my health is going down.

Also, Make sure that nothing is blocking the trainer and make sure to give it reading/writing perms.
You can do this by just putting the trainer in the same folder where you installed the game and then
restart your PC.

@BooBoo Thanks for the fast replay. I tryed the Promo Trainer. I loose Health without getting hit. As soon as i activate the Inf. Health cheat my Healthbar starts to decrease, so all 2-3 seconds i loose a part of the Healthbar without getting hit. Could it be that you accidentally uploadet the old Promo Trainer? Because i downloadet the 1.03 one but the RAR file is called 1.02.

@BooBoo Thanks for the fast replay. I tryed the Promo Trainer. I loose Health without getting hit. As soon as i activate the Inf. Health cheat my Healthbar starts to decrease, so all 2-3 seconds i loose a part of the Healthbar without getting hit. Could it be that you accidentally uploadet the old Promo Trainer? Because i downloadet the 1.03 one but the RAR file is called 1.02.

If this trainer has XP Booster x2/x4/x8/x16 like the one from Flingtrainer, it could be the best... If I'm right, it would be the best solution for the problem that one user in MAF trainer forum mention. The problem is if you get a massive amount of XP or Ability Points in one occasion, "you will lose playability of certain quests such as Portion Control in Megaris or the Arena Questline, you also permanently lose Ability Point progression on your Ubisoft Club, it also seems to stop you getting the achievement for finding 50 Orichalcum Ore"